Work on the development of radioimmunoassays to clinically and biologically important substances (prostaglandins, norepinephrine, epinephrine and histamine) will be continued. Further studies will be made of the specific ablation of antigen sensitive lymphoid cells and resistent infectious agents with cytotoxic antigen or antibody enzyme conjugates. We will also continue our work on the role of cyclic nucleotides in the activation of lymphocytic cells by lectins and antigen.